Just wondering, I recently purchased an AC Delco 170* thermostat for my 89 IROC 5.7. Will this thermostat work well in conjunction with my hypertech 4026 fan switch? I only drive the car in summer and early fall so my train of thought is the cooler the better!

I have the AC Delco P/N if needed for further clarification, i got it from reading the article about installing an aftermarket fan switch. BTW I paid almost 18.00 for the thermostat through my local GM dealership! Are they raising their prices to make up for their financial shortcomings?

 

 

yes, fans must start a little bit after the stat opens; so your configuration is ok!

 

The 4026 is the 176/166° fan switch.

I prefer the 4028, which is their 200/185° fan switch. At least the fans will turn on and off on an as needed basis with this. With the 4026, the fans will be on forever. Even with a 160° stat, the 177/166° will never get you down to 166° while driving around the city.

 

.. off at 166 F, i didn't know it!
so a 4028 fan switch or a 160 F thermostat

 

The 4026 switch is better-suited to a 160* stat, and the 4028 switch works better with a 180* stat. The better switch to use with a 170* stat is a switch in the range of 185* on/ 175* off, and somebody, Jet, I think, does sell one in that range.

But there's a full range of fan temp switches available from walk-in sources like NAPA and Car Quest, so you should be able to find a switch in any temp range you want.

But ideally, yes, the fan on/off temps should be higher than the stat temp. Othewise, the fans will run all the time.

 

^^^ Go with the 4028 fan switch.

4026 = 176/166°
4028 = 200/185°

Using the 176/166° fan switch, it won't matter if you have a 160° or 170° thermostat. Even with the 160° thermostat, the car won't be able to get down to 166° unless you're driving in cold winter weather. So if you already have a 170° thermostat, you might as well keep it. The fans will be on with either thermostat.

Our cars will shut off the fans above 40 mph regardless of fan switches, engine temps. So fan switches are only important at city speeds.

When I lived in Canada (moderate climate. Only drove the car in summer), I used to have a 160° thermostat and one of the fans programmed to turn on at 176° and off at 166°. Stock fan switch.....The primary fan would never shut off. Even when it was 15°C (60°F) outside on a cool fall evening. I'd pull in at home and sure enough, the fan would be running. Car would be about 175°F coolant temps. Once it went on, it stayed on.

I moved to the USA (near the Mexico border. Much hotter climate. I drive year round now).......I switched to a 180° thermostat and put in the 200/185° fan switch (part #4028) and never looked back. Changed the fan programming for the other fan to a higher temp.

Now it will run the fans anytime the car is in the 200-185° range. If it's below, it won't run them. Works great in summer. Works great in winter. In winter, the fans won't run. Good. I want heat in the winter..... In spring/fall, the fans might be on. They might be off. In summer, they're on just about all the time.

I guess I like the 200/185 fan switch mostly because it's good for any thermostat temperature. It's good for winter and summer. And it keeps a nice balance between being warm enough for good gas mileage while being cool enough for performance. If the car is at 184°, I don't think it needs to have the fan(s) running. Voltage will be a bit better when the fan or fans aren't running as well.